Grinder pumps are often used in low-pressure sewage systems for pumping sewage. A grinder pump includes a grinder mechanism for cutting or grinding solids or semisolid matter in the sewage being pumped. Grinding solids and/or semisolid matter in the sewage allows the resulting particulate effluent to be transferred using a pump through a small diameter pipe without clogging.
Typically, conventional sewage tanks are installed by digging a hole, placing the tank in the ground, and then pouring concrete around the bottom of the tank. The concrete provides proper ballast to prevent the tank from floating upwardly and popping out of the ground due to its buoyancy under high ground water conditions.
One particular attempt at a sewage tank by Environment One Corporation is the 2000 Series, GP 2012 grinder pump system which includes a generally cylindrical wet well sewage tank portion with a curved top edge and curved bottom edge. A plurality of hollow vertical ribs runs along the length of the tank. A single hollow horizontal rib runs along the middle of the cylindrical portion of the tank. A grinder pump is supported in the tank.
Another attempt at a sewage tank by Environment One Corporation is the 2000 Series, GP 2014 grinder pump system having a wet well sewage tank portion configured with an upper half and a lower half. The lower half is generally cylindrical with a curved bottom edge. A plurality of hollow vertical ribs runs along the length of the lower half. A single hollow horizontal rib runs along the middle cylindrical portion of the lower half. The upper half is generally cylindrical with a curved top edge. A plurality of hollow vertical ribs runs along the length of the upper half. A single hollow horizontal rib runs along the middle cylindrical portion of the upper half. To form the GP 2012 sewage tank, a two-piece mold is used, and to form the GP 2014 sewage tank, a six-piece mold is used.
There is a need for further sewage tanks and pump systems.